• Design & Manufacturing
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• 제9권2호
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• pp.20-24
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• 2015

Recently, the light guide plate (LGP), a component of the BLU, becomes thinner and larger than ever. In industrial field, specialized injection molding technique is applied to mold the ultra-thin LGP such as a ultra-high speed injection molding. Usually very high melt temperature is used for low viscosity. High injection speed and melt temperature lead to yellowing of LGP. In the present paper a series of injection molding experiment was performed under various injection molding conditions. Yellow index, CIE xy, spectral transmittance of sample were measured using the UV-Visible spectrophotometer. Systematic decrease of spectral transmittance in UV-B range was found as the melt temperature was higher. Yellow index and CIE xy were became higher near the gate location in LGP. From the result of analysis of variance, the main factor to affect for yellow index was mold temperature and that for spectral transmittance(at 315 nm) was melt temperature.

• Journal of Biosystems Engineering
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• 제33권5호
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• pp.309-316
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• 2008

The goal of this study was to develop prediction models to estimate the storage days of tomato. The transmittance spectral data measured on tomato were preprocessed through normalization, SNV, Savitzky-Golay, and Norris Gap and then were used to build the prediction models using partial least square (PLS) method. For the experiments, the tomato samples of different varieties were collected at different harvest time. The samples were taken right after harvest from the field and then were stored in a low-temperature storage room in which room temperature was maintained at $10^{\circ}C$. The transmittance spectral data of the tomato samples were measured at three-day intervals for 16 days. The performance of the prediction models was affected by the preprocessing techniques as well as the varieties and harvest time of the tomato. The best model was found when SNV was applied. The accuracy of the best model was 90.2%. It can be concluded that the transmittance spectra are useful information for predicting the period of storage of tomato.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2008년도 International Meeting on Information Display
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• pp.1366-1369
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• 2008

We introduce new instrument that provides the spectral radiance at any incidence and azimuth angle in all the visible range. LCD emission and transmittance properties of display components can be measured precisely at each incidence and azimuth angle and wavelength. Full polarization spectral analysis can be also made.

• Current Optics and Photonics
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• 제5권5호
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• pp.562-575
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• 2021

As a new type of spectrometer, that based on filters with different transmittance features attracts a lot of attention for its advantages such as small-size, low cost, and simple optical structure. It uses post-processing algorithms to achieve target spectrum reconstruction; therefore, the performance of the spectrometer is severely affected by noise. The influence of noise on the spectral reconstruction results is studied in this paper, and suggestions for solving the spectral reconstruction problem under noisy conditions are given. We first list different spectral reconstruction methods, and through simulations demonstrate that these methods show unsatisfactory performance under noisy conditions. Then we propose to apply the gradient projection for sparse reconstruction (GRSR) algorithm to the spectral reconstruction method. Simulation results show that the proposed method can significantly reduce the influence of noise on the spectral reconstruction process. Meanwhile, the accuracy of the spectral reconstruction results is dramatically improved. Therefore, the practicality of the filter-based spectrometer will be enhanced.

• 한국안광학회지
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• 제12권2호
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• pp.37-45
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• 2007

자외선 차단 소프트렌즈, 통상의 소프트렌즈 및 RGP렌즈에 대한 광투과율 스펙트럼을 ANSI Z80.20 기준에 제시된 방법으로 측정하였다. 가시광선 및 자외선에 대한 광투과율 특성을 평가하기 위하여 특정 스펙트럼 파장 영역별, 즉 가시광선, UVA, UVB 및 UVC 영역별로 적분하여 계산하였다. 가시광선 영역의 평균 투과율은 3종류의 콘택트렌즈 모두 90% 이상으로 콘택트렌즈의 광투과율 허용 범위 내에 들었다. 자외선 차단 소프트렌즈의 경우 몇 개의 렌즈를 제외하고 UVA와 UVB 영역의 광투과율은 제시된 기준에 적합하였다. 통상의 소프트렌즈와 RGP 렌즈의 자외선 차단성은 예상했던 대로 낮았다. 이런 결과들은 콘택트렌즈의 광투과율 특성에 관한 정보 활용에 있어 현장의 안경사나 실무자에게 도움이 될 것으로 기대된다.

• 한국광학회지
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• 제15권4호
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• pp.325-330
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• 2004

진공자외선 파장영역에서 광학부품의 분광특성을 측정할 수 있는 중수소광원과 진공단색화장치, 시료챔버 및 광 검출기 구조의 진공자외선 분광반사율계를 제작하였다. 제작된 진공자외선 분광반사율계는 115nm∼330 nm의 분광영역에서 약 3.0${\times}$$10^{-4}$ Pa의 기압에서 작동하였다. 253.652 nm와 184.95 nm의 수은 선스펙트럼으로 진공단색화장치의 파장을 교정하여 그 분해능이 0.012 nm이고, 파장정확도가 $\pm$0.03 nm 임을 확인하였다. 중수소 광원을 이용하여 115 nm∼230 nm 파장대역의 진공자외선 영역에서 여러 가지 광학부품들에 이용되고 있는 재료(MgF$_2$, CaF$_2$, BaF$_2$, SiO$_2$, Sapphire)들의 분광투과율과 반사율을 측정하였다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2001년도 하계학술대회 논문집
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• pp.1039-1042
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• 2001

A method for designing antireflection (AR) and antistatic (AS) films by the use of conducting polymer as an electrically conductive transparent layer is proposed. The conducting AR film is composed of four-layer with alternating high and low refractive index layer: silicon dioxide (n=1.44) and titanium dioxide (n=2.02) prepared at low temperature by sol-gel method are used as the low and high refractive index layer, respectively. The 3,4-polyethylenedioxythiophene (PEDOT) which has the sheet resistance of 10$^4$$\Omega$/$\square$ is used as a conductive layer. Optical constant of ARAS film was measured by the spectroscopic ellipsometer and from the measured optical constants the spectral properties such as reflectance and transmittance were simulated in the visible region. The reflectance of ARAS films on glass substrate was below 0.8 %R and the transmittance was higher than 95 % in the visible wavelength (400-700 nm). The measured AR spectral properties was very similar to its simulated results.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2008년도 International Meeting on Information Display
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• pp.847-850
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• 2008

Three thermally stable red dyes of azo, quinacridone and perylene derivatives were synthesized and dye-based color filters were manufactured for liquid crystal display. Aggregation behavior of the dyes and their spectral property in film state were investigated by concentration dependent spectroscopy and field emission scanning electron microscopy (FE-SEM). These dyes have remarkable difference on their aggregation behavior in film state. Such difference of aggregation behavior affects the spectral property of the film, and it can cause decreasing the transmittance of dye-based color filters.

• Journal of the Optical Society of Korea
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• 제14권3호
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• pp.190-198
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• 2010

A set of radiative transfer software named CART (Combined Atmospheric Radiative Transfer) has been developed to rapidly calculate atmospheric transmittance and background radiance. The spectral resolution of CART is $1cm^{-1}$, and the spectral region covers from 1 to $25000cm^{-1}$. CART has five characteristic features, and it can be applied to many fields. The features and applications of CART are summarized in detail.

• 한국안광학회지
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• 제19권2호
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• pp.135-143
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• 2014

목적: 국제표준에서 규정한 청색광위험함수를 도입하여 청색광차단렌즈에 대한 청색광차단율과 시감투과율을 평가한다. 방법: 8개사 총41종의 청색광차단렌즈에 대한 청색광차단율과 시감투과율을 구하기 위해 UV-VIS 분광광도계로 380~780 nm 범위에서의 분광투과율을 측정하였다. 청색광차단율은 ANSI Z80.3:2010 및 ISO 13666(한국표준 KS B ISO 13666:2004)에서 규정된 청색광위험함수를 도입하여 산출하였다. 결과: 전체 렌즈에 대한 청색광차단율 범위는 9.3%~96.8%, 투과율 범위는 53.5%~92.7%, 시감투과율 범위는 58.0%~98.1%이었다. 전반적으로 코팅 청색광차단렌즈는 시감투과율이 높은 경향이 있었고, 착색 청색광차단렌즈는 청색광차단율이 높은 경향이 있었다. 결론: 렌즈분광분포곡선의 분석으로부터 청색광차단렌즈의 성능을 향상시킬 수 있는 가능성이 있음을 확인할 수 있었다. 제조업체는 국제표준의 규정에 맞춰 성능을 평가할 수 있는 자체기술을 확보할 필요가 있다.